I downloaded the latest ConTeXt and tried regenerating the hyphenation patterns 
and formats (to get hyphenation with Thomas’ Greek module). The first step
texmfstart ctxtools --pat
was successful. But
sudo texmfstart texexec --make --all
(which worked with the last ConTeXt installation)
and
sudo -H texmfstart texexec --make --all
failed with the error message
sudo: texmfstart: command not found.
Fortunately,
sudo texexec --make --all
still works, so life goes on.

Still, why is this happening?

Does it matter that I have the line
alias texmfstart='ruby /usr/local/teTeX/share/texmf.local/scripts/context/ruby/texmfstart.rb'
in my .profile rather than an executable version of the texmfstart script in my $PATH?

If it does, is there a way to set things so that texmfstart is automatically available to the administrator and user 
whenever a Terminal session is begun?

Alan